Improvement in valves for steam-engines



Wars:

D. B. TRAVIS. VALVE EoE TEAM ENGINES.

Patented June 14. 1864.

UNITED STATES PATENT OFFICE.

o. BTRAVIS, or LA caossn, WISCONSIN.

8i IMPROVEMENT m VALVES Foe. STEAM-ENGINES- Specification forming partof Letters Patent No. 43,11), :latcil June 1-1, 1864.

To all whom it may concern: I

Be it known that I, DAVID B. TRAVIS, of

5 La Grosse, in the county of La Orosse and State of Wisconsin, haveinvented a new and useful Improvement in Steam-Engines; and I engineillustrating my improvement. Fig. 2'

is a plan of the valve-seats and horizontal section of the valves. Fig.3 is a-simila-r view to Fig. 2, but showing the parts in differentpositions. Fig. 4 is a plan of the bottom of the valve-chest.

Similarletters ofreferenceindieatclike parts.

This "invention consists in a novel system of movable valve-seats andstationary and movable ports in combination-with slide-valves in asteam-engine, whereby the engine is enabled to be reversed and stoppedvery quickly and easily.

The invention is applied in connection with two slide-valves, A A, onefor eflecting the induction and eduction of the steam to and fromoneend, and the other for effecting the induction and eduction to andfrom the other end, of the cylinder, the said "alves' being inclosedwithin a valvechest, B, to which the steam is admittc d, and the twobeing connected by a rod, 0, and worked by a rod or [width of the chest,and arranged on one side of a line drawn longitudinallyand centrallyupon the face a, and the two at each end communicate with a single steamway, (7, which communicates with their'respective end of the cylinder.The two ports 0, which are forthe exhaust, are arranged between the sameparallel lines drawn lengthwise upon the seat a,

and on the opposite side of the central longitudinal line to that onwhich b b are arranged, I

and each is arranged opposite the middle of the space between itsrespective portsb b, and the two communicate, as shown in dotted linesin Figs. 1, 2, and .4, \v'ith a. common exhaustchamber, 0. j

F F are the movable val\ e-seats, twoin number, one for each valve.Each. consists of a.

flat plate of iron faced on'bot' sides and fitted to the face a, whichmaybe called the permanentseat, and titted to work frecl y between thesides of the'valve chest or between suitabie guides provided therein,and each is made with astem,f, to enable it to be connected with oneofthe two arms g g ofa shalt, G, which is arranged perpendicular to theseat a, and fitted to a bearing in the center of the said seat, and toastriding-box, h, in the center of the cover B of the valve chest.The-said stems are arranged on' opposite sides of the said shaft, andthe said arms set in opposite directions, so that "byturning the saidshaft by m'eans of 'a. lever, H, or its equivalent, secured to itoutside of the valve-chest, the two seats may be moved in oppositedirections both toward or both from the ends of the chest. A. pinion maybe substituted for the arms 9 g to work in toothed racks on thevalve-stems. In each of the movable seats there are three ports, 01 t"j, passing through it. The ports z i are so arranged that they occupythe same space in the width of the valve-chest as the ports b b but theyare about one-third narrower in the direction of the length of thechest, and are set nearer together, the difference being a. little morethan the width of 01 e of the portsii, so that when the movable seatsare close up to the ends of the valvechest, as shown in Fig. 3, and theouter edges of the outer ports, -i i, are in the same vertical lineswith the outer edges of the outer ports, b b, the inner ports, b b,areeffectually closed by the movable seats, and when thcsa'id seats arebrought to the reverse positions shown in Fig. I, and in black outlinein Fig. 2-that is tosay-with the inner edges of thein ner ports,

ii, in the same vertical lines with the inner ports, b b-the ports I) bare etfectually closed by the valve-seats. The exhaustports j in themovable seats are arranged, like thoseot 0, in thepermanent seat-that isto say, on the op posite side of the center of the valve andmidwaybetween the two portsi i; but the exhaustports 0 in the permanentscat are made so Fir. 2.

right-hand end of the chest in Fig. 1, each in port j,and that when thesaid seatsare in the I by the movements of the valves toward theirengine is produceddcpends upon the position much wider than those of jin the movable seats that there is always free communication between thesaid ports) and c, whatever he the positions of the movable seats. Stopsk k are secured in the-permanent seat a to prevent the movable seatsapproaching each other nearer than is necessary-to bring the 'ports j tothe positionsdescribed with reference to '1" he valves A A are of sucharea that their exhaust-cavitiesl will cover-the whole three of theirrespective'portst' 1'' 'and the said valves are so set thatwhen themovable seats are in the positionreprescnted in Fig. 1 and black outlinein Fig. 2 the said valves will 11' cover and admit steam to the twoinner 1) its, 6 i, as will be seen by reference to the itsturn, andalways bring the other one into communication with its respectiveexhaustposition shown in Fig. 3, the said valves will client theinduction ot'steam to and from the two outer portsg i i. In thelast-mentioned I position of the movable seats the opening of the portsto the steam is effected by themove- 111 *nt of the valves away fromtheir respective e ids of the steam-chest, and in the first-mentionedposition of the said seats it is efi'ected respective ends 'ofthe chest,and hence the direction in which the rotary, motion of the of thevalves. It will therefore-be understood that (it is only necessary toshift the herein. set forth.

ports b b in the permanent seat a, any steam that might be in thecylinder at the time of thevalves brought to that position will escapethrough the exhaust-ports, leaving the piston free.

"In setting'the valves with 4 lead, whatever lead is given for runningthe engine in onedirection is also given in running in the oppositedirection, without changing from one wrist to another of the valverock-shaft.

I do not claim, broadly, the employment of movable valve-seats foreflecting'thc reversal of steam-engines; but- What I claim as myinvention,'amldesire to secure by Letters Patent, is

The combination, with two slide-valves, A A,

of two movable three-ported valve-seats, F F, and a system of six portsin the permanent seat, the whole. constructed, arranged, and operatingsubstantially as. and for the purpose a DAVID B. TRAVIS. Witnesses; 4 g

' HARVEY E. HUBBARD,

, A. T. CLINTON.

